Cylindrical surface finishing tool

ABSTRACT

The tool of the burnishing type has a cage at the working end of a spindle containing tapered rollers that engage a diverging truncated conical head on the end of the spindle. The opposite end of the spindle has a driven end on which a nonrotatable pressure applying unit is disposed. In one form the unit is a cylinder having a piston therein which exerts pressure on the cage supporting tube and forces the truncated conical rollers downwardly over the conical head and thereby exerts a substantial outward force on the rollers during the burnishing operation. A spring unit may be substituted for the cylinder and piston to apply the force to the sleeve and rollers.

United States Patent Kruse, Jr. [451 Apr. 18, 1972 [54] CYLINDRICALSURFACE FINISHING 527,155 10/1894 Pratt ..72/123 TOOL FOREIGN PATENTS ORAPPLICATIONS [72] Inventor: Clemens A. Kruse, Jr., 1718 Waverly,

Ann Arbor, Mich 47103 1,013,606 8/1957 Germany ..29/90 [22] Filed: May21, 1970 Primary Examiner-Lowe1l A. Larson Attorney-Hamess, Dickey &Pierce [21] Appl. No.: 39,246

[57] ABSTRACT [52] US. Cl ..72/l22, 29/90, 72/393 The tool of theburnishing type has a cage at the working end [51] Int. Cl ..B24b 39/02,B21c 37/30 of a spindle containing tapered rollers that engage adiverging [58] Field of Search ..29/90, 523; 72/ 1 l8, 1 19, 122,truncated conical head on the end of the spindle. The opposite 72/ 123,355, 393, 437, 445 end of the spindle has a driven end on which anonrotatable pressure applying unit is disposed. In one form the unit isa 5 R f s Ci cylinder having a piston therein which exerts pressure onthe cage supporting tube and forces the truncated conical rollers UNITEDSTATES PATENTS downwardly over the conical head and thereby exerts asubstantial outward force on the rollers during the burnishing MlhatSChOperation. A p g unit y be substituted for the cylinder 21413110312/1946 Jr and piston to apply the force to the sleeve and rollers.2,219,784 10/1940 Maupm 2,817,385 12/1957 Benjamin ..72/ 122 8 Claims, 5Drawing Figures BACKGROUND OF THE INVENTION Reference may be had to thepatent to John E. Gustkey, No. 3,444,714, which discloses a similar typeof tool that produces a penning operation.

SUMMARY OF THE INVENTION wearable material. As a specific example, anO-ring will be carried backwardly and forwardly over the inner wall ofthe cylinder during the movement of the piston therewith in oppositedirections. The machining operation to produce the inner wall, whethergrinding, reaming, cutting and the like, leaves minute grooves andprojections which can be said to be fine but which are coarse enough tocause substantial wear on the engaged O-ring surface. The present toolcrushes the projecting portions and moves them into the depressions andthereby produces a very fine microfinished surface on the wall.Thechange in diameter is insignificant and nothought is given to sizingthe aperture as any change in diameter will not effect the pressureengagement wherewith by the O-ring. However, the life of the O-ring issubstantially increased and the danger of too much wear, through theengagement with a rough surface over which it moves, is eliminated.

The tool embodies a cylindrical spindle having a drive and a workingend, the latter of which is formed into a truncated conical head, thetaper of which enlarges toward the end. A tubular element is providedover the spindle having a cage at the working end containing slots inwhich truncated conical rollers are carried in a manner to be movedoutwardly and inwardly when the cage and head are relatively movedlongitudinally of each other. Pressure applying means is providedbetween the spindle and the tube to produce the relative movement whichexpands and retracts the truncated conical rollers relative to the axisof the spindle. The pressure means may be a fluidfiactuated ram or aspring unit which produces a substantial outward controlled force on therollers which are thereby capable of crushing the projections on theinner wall of the cylinder when the cylinder is relatively passedthereover. With this arrangement, it will be noted that the truncatedconical rollers have the small end at the end of the cage. which permitssome shifting thereof when entering the workpiece and starting thecrushing and burnishing operation. After the rollers are passed throughthe cylinder, the pressure is removed between the rollers and spindlehead by the reverse movementtherebetween'which contracts the rollers andpermit the workpiece to be removed therefrom. A slight angularlydisposition of the rollers on the head, such as 3 or less, will causethe rollers to produce a feed to automatically advance the workpiecethereover during the humishing operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 isa view in elevation withparts in section showing a burnishing tool which embodies features ofthe present inventron;

FIG. 2 isan enlarged, broken sectional view of the pressure applyingportion of the tool illustrated in FIG. 1;

FIG. 3 is an enlarged sectional view of the structure illustrate-dinFIG. 1, taken on the line 33 thereof;

FIG. 4 is, aview of structure, similar to that illustrated in FIG...1,showing a different form of pressure applying device provided thereon,and

FIG. 5 is an'enlarged, broken sectional view of the structureillustrated in FIG. 4, showing the pressure applying portion thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 3, aburnishing tool is illustrated embodying the features of the presentinvention which includes a spindle 11 having a driving end 12 and aworking end 13. The working end has a diverging truncated conical head14 containing a threaded stud 15 which is screwed into a threadedaperture 16 on the end of the spindle 11. The driving end 12 has anenlarged body portion 17 containing an outwardly extending flange 18 forsupporting a flanged collar 19 between a thrust bearing 21 and a washer22 secured on the enlarged body portion 17 by split ring 23 disposed ina slot therein. A flange 24 on the collar 19 has a cylindrical element25 secured thereto by a plurality of screws 26.

The cylindrical element 25 has an outer cylindrical wall 27 containing athread 28. The wall has an aperture 29 therethrough containing a fitting31 by which fluid under pressure is introduced into the inner area ofthe cylindrical element 25. An inner cylindrical element 32 is threadedinto a threaded cylindrical aperture 33 of the cylindrical element 25 toprovide an annular recess 34 for receiving a washer-like piston 35. Theinner and outer walls of the piston are sealed to the inner and outerwalls of the cylindrical elements 32 and 25 by O-rings 36 and 37,respectively. The: washer-like piston 35 is retained within the annularrecess 34 by a flanged nut 38 which is screwed upon the thread 28 on thewall 27 of the cylindrical element 25 and retained in position by aplurality of set screws 39. The bottom of the washer-like piston 35 hasa plurality of apertures 41, six being employed in the piston hereinillustrated, in which springs 42 are disposed. The springs urge thepiston inwardly within the annular recess 34 for producing a retractivemovement thereto.

A thread 43 is provided on the innerlower wall of the piston to which awasher-like plate 44 is secured by a threaded engagement therewith. AnO-ring 45 seals the plate 44 to the body of the spindle 11. A cagesupporting tube or sleeve 46 is secured to a washer-like plate 47 by awasher 48 and a locking split ring 49 at one end and by a flange 51 anda thrust roller bearing 52 at the other end. The plate 47 has anaperture 53 therethrough with its outer end enlarged and threaded toreceive a fitting 54 through which a coolant is delivered to theaperture 53. The aperture is in communication with an annular slot 55 inthe wall of the sleeve 46 communicating with a plurality of apertures 56extending therethrough for deliverying the lubricant and/or flushingfluid between the spindle l1 and the sleeve 46.

The end of the tube or sleeve 46 has a thread 57 on the outer surface towhich a cage 58 is secured by a thread engagement therewith. The cagehas a plurality of axially extending slots 59 which are narrower at theworking end of the tool than at the end opposite thereto. Truncatedconical rollers 61 are disposed within the slots having a taper which isone-half of the taper of the head 1450 as to have the outer edges 62thereof disposed in parallel relation to each other and to the axis ofthe head and spindle. As illustrated in FIG. 3, the one side 63 of theslots is disposed at an angle to prevent the rollers 61 from passingcompletely through the slots while permitting .them to extend a desireddistance beyond the outer face of the cage.

Thedelivery of fluid through a tube 64 secured to the fitting 31 of thecylindrical element 25 introduces fluid under pressure in the inner endof the annular recess 34 to provide a pressure for moving the piston 35to the right. This moves the sleeve or tube 46 to the right advancingthe rollers 61 along the head 14 to produce an outward movement to therollers and the application of a substantial force to the inner wall 65of a cylindrical workpiece 66 regulated by the pressure of the fluidadvancing the piston. The workpiece 66 is secured by a clamp 67 of anyknown type to a table 68 which is reciprocably mounted on a base 69 andadvanced and retracted by a ram 71. One pass of the workpiece over therollers 61 moves the projections on the inner surfaces thereof into theadjacent depressions to produce a very low microfinish reading on thesurface which is hardened by the working process. It is to be understoodthat by mounting the roller 61 at a slight angle of not more than 3, therollers will cause the workpiece to automatically advance and feedthereover during the machining operation.

After the workpiece has passed over the rollers 61, the fluid deliveredby the tube 64 is shut off by the operation of a valve (not shown) whichdirects the fluid remaining in the cylinder to a tank by the expansionof the springs 42 and retraction of the piston 35. The retraction of thepiston 35 moves the sleeve or tube v46 to the left to retract therollers 61 along the head 14 and reduce the overall diameter of therollers so that the workpiece may be removed therefrom. The diverging ofthe head 14 toward the outer end permits the smaller end of the rollersto be engaged by the inner surface of the workpiece which permits theshifting thereof at the beginning of the bumishing operation and theassumption of the proper relationship upon initiating the bumishingoperation. This prevents the jamming of the rollers on the head as theworkpiece advances thereover.

While the tool is herein illustrated as being mounted horizontally, itis to be understood that it may be attached to a vertically drivenspindle to operate in a vertical direction. It is also to be understoodthat the same operation can be performed by the substitution of a springdevice 72 for the piston device illustrated in FIGS. 1, 2 and3. Such aspring device is illustrated in FIGS. 4 and wherein a flanged plate 73is carried on a tube or sleeve 74 by having a thicker portion 75 on theinner end provided with a flange 76. The plate 73 is secured against athrust roller bearing 77 and the flange 76 by a washer 78 locked inposition by a split spring ring 79 disposed in a slot in the portion 75.An arm 81 is secured to the plate 73 by a bolt 82 with its outer enddisposed in abutted relation to a fixed member (not herein illustrated)for preventing the rotation of the plate 73.

The arm 81 has a piston rod 83 secured thereto which extends from acylinder 84 for moving the plate 73 and sleeve or tube 74 to the leftagainst a plurality of sets of Bellevue washerlike springs 85 forcompressing the springs and retracting the rollers 61 for the purposepointed out hereinabove. A spindle 86 extends through the spring units45 and the sleeve or tube 74 for supporting the truncated conical head14, the same as that described with regard to the structure of FIGS. 1to 3. The spindle has an enlarged body portion 87 containing a thread 88on which a flanged bushing 89 is screwed and locked in position by a nut91. The bushing 89 abuts one end of the stacked pairs of springs while aflange 92 thereon engages a thrust roller bearing 94. A plate 93 isrotatably secured on the bushing 89 against the thrust roller bearing 94by a split ring 95. An arm 96 extends outwardly to the plate 93 andprevents it from rotating.

A sealing element 97 is disposed between the lefthand end of theenlarged portion 75 of the sleeve or tube 86 for preventing the coolantpassing through aperture 56 from passing outwardly from the lefthand endof the space between the spindle 86 and the sleeve or tube 74. Thepiston rod 83 retracts the sleeve or tube 74, moving it to the leftagainst the pressure of the spring units 85 for retracting the rollers61 and permitting the workpiece to be removed therefrom. As the pressureis reduced on the piston rod 83, the spring units 85 exert a pressure onthe sleeve or tube 74 to cause it to move to the right relative to thespindle 85 and head 14 to expand the roller 61 and to provide asubstantial outward pressure thereto controlled by the pressure of thefluid within the cylinder 84. The operation of the device is the same asthat of the device described in detail relative to FIGS. 1 to 3, theonly difference being the modification of structure to substitute thespring units 85 for the piston 35 employed in the first three figures.

The working force provided for the device of FIGS. 1 to 3 being thepressure of the fluid on the annular piston 35 and the retractive forceon the rollers is that produced by the expansion of the springs 41 whenthe fluid pressure is removed. In

the device of FIGS. 4 and 5, the springs are adjusted to produce adesired working pressure an the retraction of the rollers is produced bythe ram when compressing the springs 85 and which can also be used tocontrol the amount of working pressure delivered by the springs.

The tool of the present invention produces the same bumishing operationon the wall of the aperture in like workpieces although the diametersthereof may vary over a substantial range. The tool, therefore, isself-adjusting when performing like bumishing operations irrespective ofthe variation in the diameters of the apertures being burnished.

What I claim is:

1. In a bumishing tool for producing a fine finish on the inner wall ofa cylinder, a spindle having a truncated conical head, a sleeve on saidspindle having a cage containing truncated conical rollers disposed inengagement with conical surfaces of said head, means for relativelymoving the sleeve and spindle in one direction when the spindle isstationary or being driven in rotation for producing the expansion ofthe rollers and the application of substantial outward force thereto,and means for relatively moving said relatively movable means in theother direction when the spindle is stationary or when being driven inrotation for permitting the contraction of said rollers and the removalof pressure therefrom, said relatively movable means being relativelymoved in one direction by a fluid and in the other direction by springmeans.

2. A bumishing tool as recited in claim 1, wherein said fluid actuatesnonrotatable ram which applies relative movement between the sleeve andspindle when stationary or when rotating for producing substantialoutward pressure on the rollers controlled by the pressure of the fluiddelivered to the ram.

3. A bumishing tool as recited in claim 2, wherein said spring meansmoves the spindle and sleeve when stationary or when rotating to producethe relative movement between the spindle and the cage and thecontraction of the rollers when retracting said ram.

4. A bumishing tool are recited in claim 1, wherein said spring meansapplies relative movement between the spindle and sleeve when stationaryor when rotating for producing substantial outward pressure on therollers controlled by the degree of expansion of said spring means.

5. A bumishing tool as recited in claim 4, wherein said fluid meansmoves the spindle and sleeve when stationary or when rotating to producethe relative movement in retraction between the spindle and the cage andthe contraction of the rollers when compressing said spring means 6. Abumishing tool as recited in claim 3, wherein a support is provided forthe workpiece, and means for advancing and retracting said support andworkpiece relative to said rollers.

7. In a bumishing tool for producing a fine finish on the inner wall ofa cylinder, a spindle having a truncated conical head, a sleeve on saidspindle having a cage containing truncated conical rollers disposed inengagement with conical surfaces of said head, means for relativelymoving the sleeve and spindle in one direction when the spindle isstationary or when driven in rotation for producing the expansion of therollers and the application of substantial outward force thereto, meansfor relatively moving said piston and sleeve in the other direction whenthe spindle is stationary or when driven in rotation for permitting thecontraction of said rollers and the removal of pressure therefrom, anannular cylinder rotatably mounted on said spindle, and a washerlikepiston in said cylinder for moving said cage to advance the retract saidrollers.

8. A bumishing tool as recited in claim 7, wherein fluid pressureadvances said piston, and spring means for retracting said piston whenthe fluid pressure is removed therefrom.

1. In a burnishing tool for producing a fine finish on the inner wall ofa cylinder, a spindle having a truncated conical head, a sleeve on saidspindle having a cage containing truncated conical rollers disposed inengagement with conical surfaces of said head, means for relativelymoving the sleeve and spindle in one direction when the spindle isstationary or being driven in rotation for producing the expansion ofthe rollers and the application of substantial outward force thereto,and means for relatively moving said relatively movable means in theother direction when the spindle is stationary or when being driven inrotation for permitting the contraction of said rollers and the removalof pressure therefrom, said relatively movable means being relativelymoved in one direction by a fluid and in the other direction by springmeans.
 2. A burnishing tool as recited in claim 1, wherein said fluidactuates nonrotatable ram which applies relative movement between thesleeve and spindle when stationary or when rotating for producingsubstantial outward pressure on the rollers controlled by the pressureof the fluid delivered to the ram.
 3. A burnishing tool as recited inclaim 2, wherein said spring means moves the spindle and sleeve whenstationary or when rotating to produce the relative movement between thespindle and the cage and the contraction of the rollers when retractingsaid ram.
 4. A burnishing tool as recited in claim 1, wherein saidspring means applies relative movement between the spindle and sleevewhen stationary or when rotating for producing substantial outwardpressure on the rollers controlled by the degree of expansion of saidspring means.
 5. A burnishing tool as recited in claim 4, wherein saidfluid means moves the spindle and sleeve when stationary or wheNrotating to produce the relative movement in retraction between thespindle and the cage and the contraction of the rollers when compressingsaid spring means.
 6. A burnishing tool as recited in claim 3, wherein asupport is provided for the workpiece, and means for advancing andretracting said support and workpiece relative to said rollers.
 7. In aburnishing tool for producing a fine finish on the inner wall of acylinder, a spindle having a truncated conical head, a sleeve on saidspindle having a cage containing truncated conical rollers disposed inengagement with conical surfaces of said head, means for relativelymoving the sleeve and spindle in one direction when the spindle isstationary or when driven in rotation for producing the expansion of therollers and the application of substantial outward force thereto, meansfor relatively moving said piston and sleeve in the other direction whenthe spindle is stationary or when driven in rotation for permitting thecontraction of said rollers and the removal of pressure therefrom, anannular cylinder rotatably mounted on said spindle, and a washerlikepiston in said cylinder for moving said cage to advance and retract saidrollers.
 8. A burnishing tool as recited in claim 7, wherein fluidpressure advances said piston, and spring means for retracting saidpiston when the fluid pressure is removed therefrom.